Polymerization of organic acrylate monomers or mixtures thereof is well known in the art. One such method as described in U.S. Pat. Nos. 4,417,034 to Webster and 4,414,372 to Farnham et al. teaches a method in which the acrylate is polymerized in the presence of a catalyst and an initiator. This method is commonly referred to as Group Transfer Polymerization. The acrylates introduced into the reaction can be of one species producing homopolymers or several different species producing copolymers. Because of the ability to create "living" polymers it is possible to produce both random and structured copolymers by controlling the order of addition of materials.
A "living" polymer, as defined by Webster and by Farnham et al., is one which contains active terminal group(s) and is capable of polymerizing further in the presence of the catalyst and an acrylate. A terminated, or non-living, polymer is not capable of further polymerization by the group transfer polymerization method.
A common initiator for this process is a silyl ketene acetal. Although this is a siloxy-functional compound it is never incorporated into the polymer unless the polymer is maintained in the living form. At that point it is incorporated only at the polymer ends and is not along the polymer backbone. The siloxy functionality is removed from the polymer ends when the living form is terminated.
Numerous pieces of literature report on the studies that have been done on the types of acrylates, catalysts, and initiators that are applicable in the above described method for acrylate polymerization. Of the acrylates studied the number that contain silicones or siloxanes appears to be limited. It also appears that the use of organic diacrylates and silicone diacrylates which result in block copolymers has also been limited.
Both Farnham et al. and Webster teach the use of siloxy containing acrylates for use in the polymerization process. These compounds like the initiator are present along the polymer chain while in the living form. However upon termination of the reaction the siloxy group is removed from the polymer backbone resulting in a polymer that is essentially organic.
U.S. Pat. No. 4,588,795 to Dicker et al. teaches novel catalysts which are useful in the method as taught by Farnham et al. and Webster. These catalysts, in particular, are oxyanions and salts comprising suitable cations.
Other methods have been developed for acrylate polymerization. Most of these result in a polydispersed polymer, i.e. high molecular weight distribution, and require the use of a peroxide type catalyst for free radical addition.
Novelty arises in this invention due to the use of silicone acrylates that are incorporated into the polymer backbone, in both living and non-living form, and the ability to provide monodispersed polymers or those with a narrow molecular weight distribution.
It is an object of this invention to show novel silicone acrylate polymers, copolymers and block copolymers produced from silicone acrylates, silicone diacrylates, organic acrylates and mixtures thereof.
It is also an object of this invention to show a novel method for producing silicone acrylate block copolymers.
It is also an object of this invention to show improved glass reinforced polyesters by the addition of silicon acrylate polymers or copolymers to the glass.